If you ask Clarence Ditlow, the National Highway Traffic Safety Administration is trying to prevent scrutiny of regional-recall problems by no longer disclosing the city and the state of consumers who complain.

Once that information was listed in the agency's records and on its Web site. But in the last few years, the information has disappeared, said Ditlow, executive director of the Center for Auto Safety.

"This makes it very difficult for the public to analyze the inadequacies of geographic recalls," Ditlow said.

The NHTSA insists that the change was a simple error.

The cities and states on the NHTSA's Web site and in its files were removed by mistake, responded Kenneth N. Weinstein, NHTSA associate administrator for safety assurance.

Weinstein said the people responsible for blocking out names and addresses believed that it was easier to block out the entire address and did not realize that doing so was against the agency's policy. The information will be restored, he said.

In the last few years, the NHTSA has been increasingly allowing automakers to do regional recalls if the automaker can convince the NHTSA that the safety defect is most likely to occur in a specific area. Usually the regional recalls involve corrosion of a safety-related part or failures due to high temperatures.

Critics of the system, including Ditlow and former NHTSA administrator Joan Claybrook, contend that the system endangers consumers. They have demanded that the NHTSA stop the practice.

The NHTSA has defended regional recalls as a rational approach that encourages automakers to help consumers because automakers might not do a national recall. Agency officials also say they are insisting that the automakers take steps to make sure that all consumers are protected.